The instant application should be granted the priority dates of Nov. 11, 2005, the filing date of the corresponding German patent application 10 2005 054 253.0, as well as Nov. 13 2006, the filing date of the International patent application PCT/DE2006/001981.
The present invention relates to an apparatus for producing a mixture composed of various loose or bulk material components.
Conventional charge mixers have weighing containers and mixing containers which are separate from one another, with a charge in the weighing container being emptied, after it has been weighed, into the mixing container arranged underneath it. The mixing container contains mixing members which are driven by one or more motors and mix the bulk material components with one another. The complete mixture is then passed on for further processing, for example in an extruder. In addition to the increased hardware complexity, this prior art has the disadvantage of the physical height, which is relatively large, since the weighing container is arranged above the mixing container.
Known apparatuses overcome this by integrating the mixing device in the weighing container, for example as is known from EP 0 789 617 B1 and DE 196 14 688 C2. This solution therefore has no separate mixing container, thus reducing the physical height and reducing the hardware complexity. However, these solutions have the disadvantage that the mixing device, in this case in particular the drive motor together with the weighing container, is suspended on the weighing device, and/or is supported on it. This has a negative influence on the ratio of the empty weight of the weighing container to the items being weighed, thus resulting in measurement errors. A further disadvantage of the apparatuses known from DE 196 14 688 C2 and EP 0 789 617 B1 is that the weighing container must be caused to oscillate in order to mix the charge located in it, thus likewise increasing the hardware complexity.
DE 70 26 426 U discloses an apparatus of this generic type in which the mixing device projects into the weighing container from above. The mixing device is driven by a motor which is mounted, gravimetrically separately from the weighing container, on a framework of the apparatus. The motor and the mixing apparatus are connected by a claw clutch. During the mixing phase, the motor is connected via the claw clutch to the mixing device, while the claws of the claw clutch assume a position without any force and contact during the weighing phase. The mixing device is therefore gravimetrically separated from the motor during the weighing phase.
This apparatus has the advantage over the other known apparatuses that the drive unit for the mixing device is not also weighed, therefore improving the ratio of the empty weight of the weighing container to the items being weighed, in order to increase the measurement accuracy.
The object of the present invention is to provide an apparatus of this generic type in which the ratio of the empty weight of the weighing container to the items being weighed is improved even further, in order to increase the measurement accuracy.